A 56-acre estate in Mill Neck once owned by members of the Pratt and Rockefeller families has hit the market. It’s listed for $30 million.

“It’s probably one of the last pieces of property of this magnitude on the North Shore,” says owner William Catacosinos, a senior partner at Laurel Hill Advisory Group, a corporate communications firm, and the former chairman of Long Island Lighting Company.

When Catacosinos and his late wife, Florence, first visited the property in the late 1970s, “we drove in and we were awed by the splendor of the place,” he says. Over time, he says, the Rockefellers had acquired surrounding parcels as they became available to amass the property, which records show is composed of 10 separate lots.

Another buyer at the time, Catacosinos adds, was set to buy the property and subdivide.

“I said, ‘This place is so beautiful, you can’t break it up. It would be criminal to do it,’ ” he says. “We negotiated for a year to try and buy it, and we couldn’t.”

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Catacosinos later received a call from Rockefeller’s representatives saying the buyer never closed on the sale. “So we were able to buy it in one piece,” he says.

KNOWN AS LAUREL HILL

The estate, now known as Laurel Hill, was purchased by the Catacosinoses in 1978 from the estate of Abby Rockefeller Mauzé, the granddaughter of oil tycoon John D. Rockefeller. It includes a 10,000-square-foot Tudor manor house, a three-bedroom cottage, a two-bedroom carriage house and a two-bedroom pool house.

The baronial-style main house includes a foyer with dual parlors, a library, a banquet room, a master suite with his and hers bathrooms, and a guest wing, he adds.

Catacosinos’ favorite room in the house is what he calls “The Red Room,” a library with red furniture, built-in bookshelves and one of the home’s seven fireplaces.

The house, built in 1928, according to the property records, retains many original features, including the call system used to communicate from room to room, says Jason Friedman of Daniel Gale Sotheby’s International Realty, who is co-listing the property with Rudi Friedman of Daniel Gale Sotheby’s International Realty and Robert J. Olita and John J. Martin of Douglas Elliman Real Estate. The interior of the house has been updated, Friedman adds, while maintaining the character of the house.

“We wanted to keep it the way it was built,” Catacosinos says. “And my wife wanted the grounds to be natural because it’s a haven for a lot of creatures: large turtles, rabbits, fox, hawks, deer.”

10 LOTS, 1 SERENE ESTATE

The estate has wrought iron gates and a tree-lined driveway that stretches for a half-mile. The property also includes a cobblestone courtyard, a gunite pool, a tennis court, a sports court, a greenhouse and two garages.

“I don’t know if there are any properties left [on Long Island] that big,” Friedman says.

Four decades after buying the estate, Catacosinos still refuses to subdivide, saying he will sell it as one serene property.

“My wife is no longer with us, but she would be very unhappy with me if it was broken up,” he says. “With the serenity of the house and surrounding grounds, it’s a very special place.”